Sealing apparatus for gas compressor

ABSTRACT

Apparatus for sealing the rotor shaft of gas compressor by sealing liquid fed under pressure comprising equalizing gas chambers, sealing liquid chambers, a head tank to feed the sealing liquid into the sealing liquid chambers, and means for regulating the pressure in the head tank according to the operating condition of the gas compressor.

United States Patent 1191 Endo et al.

[ SEALING APPARATUS FOR GAS COMPRESSOR [76] Inventors: Takamasa Endo, 3-22-302 S-chome;

Shojiro Sugimura, 7436 Chikko, both of Tamano. Okayama. Japan [22] Filed: Dec. 8. 1971 [21] Appl. No.: 205.918

[30] Foreign Application Priority Data Dec. 16, 1970 Japan 45-112107 [52] [1.8. CI. 415/175 [51] Int. Cl. F0ld 5/06 [58] Field of Search 415/175. 176

[56] References Cited UNITED STATES PATENTS 2.347.751 5/l944 Reeves et al 415/176 Mar. 19, 1974 2.608.380 8/1952 Rice 415/175 3.532.444 10/1970 Strub 415/175 FOREIGN PATENTS OR APPLICATIONS 1.125.782 7/1956 France 415/175 207.476 1/1956 Australia 415/175 Primary Examiner-Henry F Raduazo Attorney. Agent, or Firm-Howson and Howson:

Henry H. Skillman [57] ABSTRACT Apparatus for sealing the rotor shaft of gas compressor by sealing liquid fed under pressure comprising equalizing gas chambers, sealing liquid chambers. a head tank to feed the sealing liquid into the sealing liquid chambers, and means for regulating the pressure in the head tank according to the operating condition of the gas compressor.

1 Claim, 3 Drawing Figures PATENTEDHAR 19 I974 sum 1 0F 3 FIG.1

PRIOR ART PATENTEDKAR 19 I974 SHEET 2 0F 3.

FIG. 2

PRIOR ART 1 SEALING APPARATUS FOR GAS COMPRESSOR This invention relates to a rotary gas compressor, and more particularly to a sealing mechanism for the gas compressor.

An object of this invention is to provide a novel sealing apparatus for adjusting pressure of sealing liquid. which is simplified construction.

This invention will be better understood from the following description taken in connection with the accompanying drawings in which:

FIG. 1 is a diagrammatic illustration of a gas compressor provided with a conventional sealing apparatus;

FIG. 2 is an enlarged sectional view of sealing apparatus in FIG. 1; and

FIG. 3 is a diagrammatic illustration of a gas compressor provided with the sealing apparatus according to the present invention.

In general, the conventional rotary gas compressor generally designated by A in FIGS. 1 and 2 are provided with equalizing gas chambers C, sealing liquid chambers D and atmospheric chambers E which are arranged in side by side relation on both sides of rotor B, was to prevent leakage of operating fluid by suitably selected pressure relation among these chambers. In each sealing liquid chamber D is provided with a sealing sleeve F such as shown in FIG. 2, and sealing liquid under pressure is fed into the chambers D from a head tank G positioned at a higher level than the chamber assemblies. To the head tank G is supplied sealing liquid, from a sealing liquid tank H located at a lower position than the gas compressor A, under control of a liquid level controller I. Since the head tank G is connected to the equalizing chambers C of the gas compressor. sealing liquid is supplied under higher pressure than that of the equalizing chambers by the pressure corresponding to the difference of height between the tank G and the chamber C. Accordingly, the sealing liquid supplied to the sealing liquid chambers D through a sealing liquid supply pipe line J and the spaces between the rotor and partition walls of the respective chambers flows into equalizing gas chambers C and atmospheric chambers E respectively. The liquid flown into the atmospheric chambers E is returned to the tank H through drain pipes K. The liquid flows into the equalizing gas chambers C is discharged into a waste liquid tank M through drain pipes L. because the liquid may be contaminated by operating fluid in the gas compressor A.

The sealing liquid discarded into the waste liquid tank M must be limited to a small amounts for operating economy of the gas compressor. Accordingly it has been usually practiced to adjust pressure of the sealing liquid by changing the mounting position of the head tank G according to the operating condition of the compressor. Such measures, however, entail manufacturing cost of the apparatus for adjusting the mounting position of the head tank G and additionally, it is difficult to change the mounting position without stopping operation of the compressor.

The present invention provides a simple apparatus which can adjust the pressure of the sealing liquid. A feature of the present invention resides in an arrangement in which pressure gas in the gas compressor is fed into the head tank correspondingly to the difference between pressures in the top space in the head tank and in the equalizing gas chambers. thereby to maintain pressure in the head tank at a desired level.

Referring to FIG. 3, same reference numerals are used to denote the same parts as in the arrangement of FIGS. 1 and 2, and explanation of these parts. which has already been made in connection to FIGS. 1 and 2. is not repeated here.

A pressure supply pipe line 2 branched off from an exhaust pipe 1 of the gas compressor A is connected to the top of the head tank G, and a flow rate control valve 3 is incorporated in the pressure supply pipe line 2. Also connected into the top space in the head tank G is a pressure pipe line 4 the other end of which is connected to the equalizing gas chambers C of the gas compressor A, and an orifice 5 is provided in the pressure pipe line 4. On the upand down-stream sides of the orifice 5 are connected the pressure detecting pipe lines 6 and 7, respectively, and a pressure controller 8 operated in response to the difference of pressure between said pressure detecting pipe lines 6 and 7 is connected to the other ends of the pipe lines 6 and 7, the output of the pressure controller 8 being adapted to regulate the pilot section of the flow rate control valve 3.

In order to facilitate smooth pressure transmission from the equalizing gas chambers C to the head tank G, a check valve 9 may be incorporated in parallel to the orifice 5.

In operation, it is possible to maintain pressure in the head tank G at a higher level than pressure in equalizing gas chambers C by suitably adjusting the set condition of pressure controller 8. Of course, the liquid level in head head tank G is maintained independently by the liquid level controlling means I. Thus, pressure in the sealing liquid chambers D is the sum of potential head of head tank G and internal pressure of the tank. Accordingly, even if the head tank G is fixed stationary, it is possible to obtain adequate sealing pressure corresponding to the operating condition of the gas compressor A by merely changing the pressure in the head tank G. Further, during the normal operating condition, pressure in equalizing gas chambers C is compared with the internal pressure of head tank G and the internal pressure in the head tank G is kept at a level corresponding to the condition of operation, so that the amount of wasted sealing liquid is minimized. Still further, the present invention prevents a danger of burning of seal sleeve F in the sealing liquid chambers D due to shortage of sealing liquid supplied into the equalizing gas chambers as often experienced in the conventional sealing devices. Moreover, it is possible with the present invention to freely change the sealing pressure during operation of the gas compressor.

We claim:

1. Sealing apparatus for a rotary gas compressor having a rotor shaft and an exhaust pipe for the compressed gas. said apparatus comprising equalizing gas chambers, sealing liquid chambers and atmospheric chambers which are arranged adjacent each other in succession along the axis of the rotor shaft, a fixed head tank having a liquid outlet directly connected to said sealing liquid chambers to feed the sealing liquid into said sealing liquid chambers and a gas inlet to receive gas therein to control the pressure of said liquid. a pressure supply pipe line connecting exhaust pipe of said gas,,compressor to the gas inlet of said head tank, a flow rate control valve in the pressure supply pipe line, and

ence of detected pressures so as to maintain a pressure in the head tank at a level corresponding to the operating condition of the gas compressor.

Patent No. 3 Dated MarCh Inventofls) Takamasa Endo and Shojiro Sugimura It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

In the heading, after "Inventors" insert the following:

-- [73] Assignee: Mitsui Shipbuilding and Engineerin Co. Ltd. Tokyo, Japan Signed and sealed this 9th day of July 1974.

(SEAL) Attest:

McCOY M. GIBSON, JR. C. MARSHALL DANN Attesting Officer Commissioner of Patents U.S. GOVERNMENT PRINYING OFFICE: I). 0-316-334. 

1. Sealing apparatus for a rotary gas compressor having a rotor shaft and an exhaust pipe for the compressed gas, said apparatus comprising equalizing gas chambers, sealing liquid chambers and atmospheric chambers which are arranged adjacent each other in succession along the axis of the rotor shaft, a fixed head tank having a liquid outlet directly connected to said sealing liquid chambers to feed the sealing liquid into said sealing liquid chambers and a gas inlet to receive gas therein to control the pressure of said liquid, a pressure supply pipe line connecting exhaust pipe of said gas compressor to the gas inlet of said head tank, a flow rate control valve in the pressure supply pipe line, and comparison means for detecting pressure in said equalizing gas chambers and pressure in said head tank respectively, said comparison means being connected to said flow rate control valve to regulate said flow rate control valve by a signal corresponding to the difference of detected pressures so as to maintain a pressure in the head tank at a level corresponding to the operating condition of the gas compressor. 